Rfid control dart

ABSTRACT

A control dart having an internal power supply includes an RFID reader adapted to read one or more RFID tags positioned within a tool string. In response to reading an RFID tag having a selected identification code, the control dart may extend one or more locking dogs. When extended, the locking dogs allow the control dart to actuate a downhole tool.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a nonprovisional application which claims priority from U.S. provisional application No. 61/976,128, filed Apr. 7, 2014, the entirety of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD/FIELD OF THE DISCLOSURE

The present disclosure relates generally to tools for use in a wellbore, and specifically to a control dart for a selectively openable port sleeve for use in hydraulic fracturing operations.

BACKGROUND OF THE DISCLOSURE

During the drilling of a well for oil and gas, in some earthen formations, oil and gas production may be significantly increased through the use of enhanced oil recovery including hydraulic fracturing. In a hydraulic fracturing operation, a mixture of fluid and proppant (referred to herein as fracturing fluid) is pumped at high pressure into the formation, causing the formation to fracture. Proppant, such as sand, is included in the fracturing fluid to, for example, help keep the fractures open and thus increase porosity of the formation. In order to fracture a formation, a downhole tool, referred to herein as a hydraulic fracturing string, is placed within the wellbore. The hydraulic fracturing string may include a number of downhole tools including packers, cement collars, and one or more fracturing sleeves. A fracturing sleeve is a downhole tool which includes one or more apertures which may be opened to allow the hydraulic fracturing of the formation surrounding it.

In some instances, the hydraulic fracturing string including the fracturing sleeves is cemented in the wellbore before the hydraulic fracturing operation takes place. The fracturing sleeves are then opened sequentially, through the use of, for example, hydraulic pressure, control balls, control darts, or electromechanical operations, and fracturing fluid is pumped at high pressure into the surrounding wellbore to complete the fracturing operation. The downhole environment in which the fracturing sleeves are located may be very harsh and may lead to damage of any electronic equipment placed therein.

SUMMARY

The present disclosure provides for an RFID control dart for use with a downhole tool. The RFID control dart may include an outer cover, the outer cover being generally cylindrical in shape; at least one locking dog adapted to, when in an extended position, extend in a generally radial direction from the outer cover and, when in a retracted position, remain generally within the outer cover; an electronic controller, the electronic controller including an RFID reader, the electronic controller adapted to extend or retract the locking dog in response to reading a preselected identification code from an RFID tag with the RFID reader; and a power source adapted to provide electric power to the electronic controller and the at least one locking dog.

The present disclosure also provides for a method for reconfiguring a downhole tool. The method may include providing an RFID control dart. The RFID control dart may include an outer cover, the outer cover being generally cylindrical in shape; at least one locking dog adapted to, when in an extended position, extend in a generally radial direction from the outer cover and, when in a retracted position, remain generally within the outer cover; an electronic controller, the electronic controller including an RFID reader, the electronic controller adapted to extend or retract the locking dog in response to reading a preselected identification code from an RFID tag with the RFID reader; and a power source adapted to provide electric power to the electronic controller and the at least one locking dog. The method may further include providing a downhole tool. The downhole tool may be coupled to a tool string. The downhole tool may be adapted to be actuated by the control dart when the locking dogs are in the extended position. The method may also include positioning at least one RFID tag at a position generally closer to the surface than the downhole tool, the RFID tag readable by the RFID reader and having a unique identification code, the RFID tag being an unpowered, passive type RFID tag; configuring the RFID control dart with an identification code corresponding to the identification code of the RFID reader; pumping the RFID control dart through the tool string; reading the identification code with the RFID reader; matching the identification code read by the RFID reader with the preprogrammed code; extending the locking dogs; actuating the downhole tool.

The present disclosure also provides for a system. The system may include an RFID control dart for use with a downhole tool. The RFID control dart may include an outer cover, the outer cover being generally cylindrical in shape; at least one locking dog adapted to, when in an extended position, extend in a generally radial direction from the outer cover and, when in a retracted position, remain generally within the outer cover; an electronic controller, the electronic controller including an RFID reader, the electronic controller adapted to extend or retract the locking dog in response to reading a preselected identification code from an RFID tag with the RFID reader; and a power source adapted to provide electric power to the electronic controller and the at least one locking dog. The system may also include a downhole tool, the downhole tool coupled to a tool string, the downhole tool adapted to be actuated by the control dart when the locking dogs are in the extended position. The system may also include an RFID tag coupled to the tool string positioned generally closer to the surface than the downhole tool, the RFID tag readable by the RFID reader and having a unique identification code, the RFID tag being an unpowered, passive type RFID tag.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 depicts an overview of a hydraulic fracturing operation consistent with embodiments the present disclosure.

FIG. 2 a depicts an RFID control dart consistent with embodiments of the present disclosure in the retracted position.

FIG. 2 b depicts an RFID control dart consistent with embodiments of the present disclosure in the extended position.

FIGS. 3 a-d depict an RFID control dart passing through a fracturing string consistent with embodiments of the present disclosure

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

FIG. 1 depicts an overview of a hydraulic fracturing operation consistent with embodiments of the present disclosure. Hydraulic fracturing string 101 is placed into wellbore 10 by drilling rig 20. Hydraulic fracturing string 101 is positioned so that fracturing sleeves 103 are aligned with the section of wellbore 10 desired to be hydraulically fractured. In some embodiments, hydraulic fracturing string 101 includes cementing collar 105 which serves to, for example, allow cement 107 to flow from the interior of hydraulic fracturing string 101 to the annular space between hydraulic fracturing string 101 and wellbore 10. In some embodiments, hydraulic fracturing string 101 may also include packer 109 to, for example, contain cement 107 within only the desired section of wellbore 10. Packer 109 may be an inflatable packer, swellable packer, or any other zonal isolation packer known in the art.

Once cement 107 has cured or packers are set, the fracturing operation may commence. Fracturing sleeves 103 may be selectively opened (as discussed below), allowing for fluid communication between the interior of hydraulic fracturing string 101 and wellbore 10. High pressure fracturing fluid is introduced into hydraulic fracturing string 101 and passes through the open fracturing sleeve 103 to hydraulically fracture (12) the surrounding formation. Subsequently, another fracturing sleeve 103 may be opened, and the fracturing operation may continue.

In some embodiments of the present disclosure, one or more fracturing sleeves 103 may be actuated by an RFID control dart. As depicted in FIGS. 2 a, 2 b, RFID control dart 201 may be generally cylindrical in shape and include outer cover 203. Outer cover 203 may have a rounded or tapered nose 205 adapted to, for example, allow RFID control dart 201 to more easily traverse the interior of a tubular. RFID control dart 201 may be adapted to be pumped through a tool string, such as the previously discussed hydraulic fracturing string and selectively engage with one or more sliding sleeves. As depicted in FIG. 2 b, RFID control dart 201 may include one or more extendible locking dogs 207. Locking dogs 207 may be selectively extended or refracted by an electronic controller positioned within RFID control dart 201. In some embodiments, the electronic controller may include an RFID reader. As understood in the art, an RFID, or radio-frequency identification, reader may include a radio transceiver capable of recognizing an identification code stored in one or more RFID tags. RFID tags, as understood in the art, may be active or passive circuits designed to, when interrogated by an RFID reader, transmit their unique identification code to the RFID reader.

In some embodiments, the electronic controller may also include a power source and an electrical actuator adapted to extend or retract locking dogs 207. In some embodiments, in response to detecting an RFID tag having a predetermined identification code, the electronic controller may cause the extension of locking dogs 207.

In some embodiments, RFID control dart 201 may also include one or more seals 209 adapted to seal RFID control dart 201 within a tubular member. Seals 209 may, for example, allow RFID control dart 201 to be pumped by fluid pressure through the tubular. Additionally, seals 209 may, for example, allow fluid pressure to be transferred through RFID control dart 201 into a downhole tool having a dart catcher as described below.

In some embodiments of the present disclosure, each fracturing sleeve 103 as depicted in FIG. 1 may include an RFID tag with a known and unique identification code. The electronic controller of RFID control dart 201 may be configurable to activate when a specific RFID tag identification code is detected. As understood in the art, passive type RFID tags may be powered or unpowered. Because of the harsh environment in wellbore 10, any power sources such as batteries may be corroded or otherwise destroyed before being used. In some embodiments of the present disclosure, the RFID tags may be unpowered, passive type RFID tags. As understood in the art, an unpowered, passive type RFID tag responds, as previously discussed, to an interrogation signal from the RFID reader with its identification code while not relying on a dedicated power source other than that attached to the RFID reader. Additionally, the RFID tags may be protected from the downhole environment by, for example, being installed or attached in the wall of the corresponding fracturing sleeve 103. In some embodiments, the RFID tags may be installed or attached in a separate tubular or casing device. In some embodiments, the RFID tags may be selectively attachable to the outside or inside wall of a tubular of the tool string.

As depicted in FIG. 3 a, RFID control dart 201 is pumped through hydraulic fracturing string 101. As RFID control dart 201 passes through each fracturing sleeve 303 a-d, the electronic controller detects the identification code of each RFID tag 305 a-d. As an example, RFID control dart 201 may be configured to reconfigure RFID control dart 201 and extend locking dogs 207 when a target identification code corresponding with that of RFID tag 305 b of fracturing sleeve 303 b is received.

In operation, RFID control dart 201 is pumped through fracturing string 101 with locking dogs 207 in a retracted position, thus allowing it to pass freely through dart catchers 307 a-d positioned within each fracturing sleeve 303 a-d. As RFID control dart 201 passes through fracturing sleeve 303 a, the identification code of RFID tag 305 a is received. RFID control dart 201 recognizes that this identification code does not match the preselected target identification code. Locking dogs 207 thus remain in the retracted position.

As depicted in FIG. 3 b, as RFID control dart 201 passes through fracturing sleeve 303 b, the identification code of RFID tag 305 b is received. RFID control dart 201 recognizes that this identification code does match the target identification code. As a result, locking dogs 207 are extended as RFID control dart 201 moves from fracturing sleeve 303 b to 303 c.

As RFID control dart 201 moves through fracturing sleeve 303 c, the extended locking dogs 207 interfere with dart catcher 307 c of fracturing sleeve 303 c, thus retaining control dart 201 within fracturing sleeve 303 c as depicted in FIG. 3 c. Once RFID control dart 201 is captured, fluid pressure applied to control dart 201 may be transferred into fracturing sleeve 303 c. In some embodiments, fracturing sleeve 303 c may include a sliding sleeve 309 c adapted to open one or more apertures 311 c when sliding sleeve 309 c is moved by RFID control dart 201. As depicted in FIG. 3 d, fluid pressure exerted on RFID control dart 201 may cause sliding sleeve 309 c to slide, thus selectively opening apertures 311 c.

Although described in terms of a fracturing sleeve, one having ordinary skill in the art with the benefit of this disclosure will understand that RFID control dart 201 may be used to control any downhole tool actuatable by a control dart. For example, the downhole tool may be, without limitation, a sliding sleeve for production or injection control, primary or secondary cementing tool, production testing chamber or device, actuation mechanism for setting a packer, liner hanger or similar device, choke for production or injection control, or a tool for selectively setting a tubing or casing plug in a particular location to control production or injection. By replacing a standard dart catcher with a dart catcher configured to only catch RFID control dart 201 when locking dogs 207 are in the extended position, any such downhole tool may be reconfigured to use RFID control dart 201. Furthermore, in some embodiments, RFID control dart 201 may include features common to standard downhole darts, including, without limitation, one or more wipers.

The foregoing outlines features of several embodiments so that a person of ordinary skill in the art may better understand the aspects of the present disclosure. Such features may be replaced by any one of numerous equivalent alternatives, only some of which are disclosed herein. One of ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. One of ordinary skill in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure. 

1. An RFID control dart for use with a downhole tool, the RFID control dart comprising: an outer cover, the outer cover being generally cylindrical in shape; at least one locking dog adapted to, when in an extended position, extend in a generally radial direction from the outer cover and, when in a retracted position, remain generally within the outer cover; an electronic controller, the electronic controller including an RFID reader, the electronic controller adapted to extend or retract the locking dog in response to reading a preselected identification code from an RFID tag with the RFID reader; and a power source adapted to provide electric power to the electronic controller and the at least one locking dog.
 2. The RFID control dart of claim 1, wherein the outer cover further comprises a generally rounded nose.
 3. The RFID control dart of claim 1, wherein the outer cover further comprises at least one seal adapted to seal between the RFID control dart and a surrounding tubular.
 4. The RFID control dart of claim 1, wherein the RFID control dart is adapted to be pumped through a tool string and the electronic controller is adapted to read RFID tags positioned generally on or near components of the tool string.
 5. The RFID control dart of claim 4, wherein the RFID tags positioned generally on or near components of the tool string comprise unpowered, passive type RFID tags.
 6. The RFID control dart of claim 1, wherein the power source is a battery.
 7. A method for reconfiguring a downhole tool comprising: providing an RFID control dart, the RFID control dart including: an outer cover, the outer cover being generally cylindrical in shape; at least one locking dog adapted to, when in an extended position, extend in a generally radial direction from the outer cover and, when in a retracted position, remain generally within the outer cover; an electronic controller, the electronic controller including an RFID reader, the electronic controller adapted to extend or retract the locking dog in response to reading a preselected identification code from an RFID tag with the RFID reader; and a power source adapted to provide electric power to the electronic controller and the at least one locking dog; providing a downhole tool, the downhole tool coupled to a tool string, the downhole tool adapted to be actuated by the control dart when the locking dogs are in the extended position; positioning at least one RFID tag at a position generally closer to the surface than the downhole tool, the RFID tag readable by the RFID reader and having a unique identification code, the RFID tag being an unpowered, passive type RFID tag; configuring the RFID control dart with an identification code corresponding to the identification code of the RFID reader; pumping the RFID control dart through the tool string; reading the identification code with the RFID reader; matching the identification code read by the RFID reader with the preprogrammed code; extending the locking dogs; actuating the downhole tool.
 8. The method of claim 7, wherein the tool string includes at least one other downhole tool and at least one other RFID tag having an identification code different from the identification code programmed into the RFID control dart; and the method further comprises: reading the other RFID tag; comparing the programmed identification code with the identification code of the other RFID tag.
 9. The method of claim 7, wherein the downhole tool further comprises a dart catcher, the dart catcher adapted to catch the RFID control dart when the locking dogs are extended and allow the RFID control dart to pass therethrough when the locking dogs are refracted.
 10. The method of claim 7, wherein the downhole tool is a sliding sleeve, the tool string is a hydraulic fracturing string, and the control dart, when locking dogs are extended, actuates an inner sleeve of the sliding sleeve to open one or more apertures in the sliding sleeve.
 11. The method of claim 7, wherein the power source is a battery.
 12. The method of claim 7, wherein the downhole tool comprises one of a sliding sleeve for production or injection control, primary or secondary cementing tool, production testing chamber or device, actuation mechanism for setting a packer, liner hanger or similar device, choke for production or injection control, or a tool for selectively setting a tubing or casing plug in a particular location to control production or injection
 13. A system comprising: an RFID control dart for use with a downhole tool, the RFID control dart including: an outer cover, the outer cover being generally cylindrical in shape; at least one locking dog adapted to, when in an extended position, extend in a generally radial direction from the outer cover and, when in a retracted position, remain generally within the outer cover; an electronic controller, the electronic controller including an RFID reader, the electronic controller adapted to extend or retract the locking dog in response to reading a preselected identification code from an RFID tag with the RFID reader; and a power source adapted to provide electric power to the electronic controller and the at least one locking dog; and a downhole tool, the downhole tool coupled to a tool string, the downhole tool adapted to be actuated by the control dart when the locking dogs are in the extended position; an RFID tag coupled to the tool string positioned generally closer to the surface than the downhole tool, the RFID tag readable by the RFID reader and having a unique identification code, the RFID tag being an unpowered, passive type RFID tag.
 14. The system of claim 13, wherein the preselected identification code matches the unique identification code of the RFID tag.
 15. The system of claim 13, wherein the outer cover further comprises a generally rounded nose.
 16. The system of claim 13, wherein the outer cover further comprises at least one seal adapted to seal between the RFID control dart and a surrounding tubular.
 17. The system of claim 13, wherein the RFID control dart is adapted to be pumped through the tool string.
 18. The system of claim 13, wherein the power source comprises a battery.
 19. The system of claim 13, wherein the downhole tool further comprises a dart catcher, the dart catcher adapted to catch the RFID control dart when the locking dogs are extended and allow the RFID control dart to pass therethrough when the locking dogs are refracted.
 20. The system of claim 19, wherein the downhole tool is a sliding sleeve, the tool string is a hydraulic fracturing string, and the control dart, when locking dogs are extended, actuates an inner sleeve of the sliding sleeve to open one or more apertures in the sliding sleeve.
 21. The system of claim 13, wherein the RFID tag is encapsulated from the downhole environment.
 22. The system of claim 13, wherein the downhole tool comprises one of a sliding sleeve for production or injection control, primary or secondary cementing tool, production testing chamber or device, actuation mechanism for setting a packer, liner hanger or similar device, choke for production or injection control, or a tool for selectively setting a tubing or casing plug in a particular location to control production or injection. 